I've got a 2.5 year old Macbook Pro. 2.2GHz, 4GB 667MHz DDR2 RAM, 5400RPM hard drive, but my video for iMovie (capture and editing) is on an external Firewire 400 1TB. I have a tape-based HD camcorder and, being one to like to be future proofed with my home video, capture at Full resolution instead of Large. Of course I see the message telling me that there may be playback performance problems, but I'd hate to come back in 3 or 4 years time and say, "Gee, now I wish I had captured that 20 hours of home video and run stabilization analysis in HD." So it captures at anywhere from 3/4 speed to 1/8 speed, but at least it captures. Playback, however, is in fact very jerky. Sometime in the coming year (hopefully when they release i7-based Macs) I'll be getting a new system, so I'm contemplating whether to get an iMac and get more power while cleaning off the clutter on the desk (external monitor) or get a Macbook Pro and get mobility. I don't really need the mobility since 95% of the time my Mac stays parked at my desk, but there's always that *one* time that I need to go show something off. But that said, do you guys think it's the 5400RPM hard drive causing the bottleneck (not sure if iMovie running from the internal is much of a factor), or more likely the FW400 external drive? I'd hate to get a brand new iMac only to be afflicted by the same issue. Am I just stuck waiting until I'm an old man and someone creates a 2TB SSD drive to be sold for $100?